Refrigerant evaporator



June 13, 1939. D. F. NEWMAN REFRIGERANT EVAPORAIOR Filed June 12, 1957 "Fig.3.

Inventor: Delbert F. Newman,

b 29 M1 6 JWLM, 9 His Attorney.

Patented June 13, 1939 UNITED STATES 2,162,586 REFRIGERAN T EVAPORATOR Delbert F. Newman, Schenectady, N. Y., assignor to General Electric Company, a corporation of v New York Application June 12, 4937, Serial No. 147,946

Claims.

My invention relates to evaporators for refrigcrating machines and particularly to suchevaporators constructed of sheet metal and provided with a plurality of refrigerated surfaces for sup- 5 porting freezing trays and the like.

Refrigerant evaporators are frequently con- .tructed of sheets of metal provided with indentations forming passages for the refrigerant and bent into shape to form a freezing chamber. The

bottom walls of such evaporators normally are refrigerated so that trays of water, desserts, or the like may be placed thereon for freezing. When it is desired to provide greater freezing'tray capacity, shelves are arranged within the freez- 5 ing chambers and are provided with refrigerant circulating conduits so that additional freezing trays may be used. When constructing the evaporator of sheet metal it is desirable to form the evaporator with a minimum number of operations and furthermore to avoid as much as possibie soldered joints or connections for conveying refrigerant from one portion of the evaporator to the other.

Accordingly, it is an object of my invention to provide an improved evaporator for refrigerating machines having a plurality of freezing tray supporting surfaces and which shall be of simple construction and require aminimum number of soldered connections.

a0 Another object of my invention is to provide an improved evaporator for refrigerating ma-- chines having a plurality of freezing tray sup porting-surfaces and which may readily be constructed from a single wall structure of sheet gg, metal.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a partof this specification.

For a better understanding of my invention reference may be hadto the accompanying drawing in which Fig. l is a front elevation view of a household refrigerating machine provided with an evaporator embodying my invention; Fig. 2 is an enlarged perspective rear view of 'the. evaporator shown in Fig. l; and Fig. 3 is a plan view of the sheet metal structure of the evaporator in the flat prior to bending.

Referring now to the drawing,'in Fig. l I have shown a household refrigerator comprising a cabinet Hi having a door I! shown in its open position and provided with a removable top l2. On the removable top i2 is mounted a refrigerating machine comprising a casing l3 containing a motor and a compressor, a condenser it formed in a shell I 5, a liquid receiver or float valve chamber l6, and an evaporator ll arranged within the food compartment of the cabinet Ill. During 5 the operation of the refrigerating machine, gaseous refrigerant is compressed by the compressor within the casing l3 and is discharged into the condenser I l. The hot compressed refrigerant within the condenser ll is cooled by the cir- 1 culation of airover the shell l5 and is thereby liquefied, the liquid refrigerant flowing through a connection l8 into the float valve chamber It. When a predetermined amount of liquid refrigerant has collected in the chamber IS a float 15 therein rises and liquid refrigerant flows from the chamber 16 through a connection l9 to the evaporator H. The liquid refrigerant within the evaporator l'l absorbs heat from the freezing trays or other articles placed therein and from 20 the air in the food compartment of thecabinet; this absorption of heatvaporizes the liquid refrigerant which is withdrawn from the evaporator through a suction conduit 20 and is returned to the casing iii.

The construction of the evaporator II may be clearly seen in Fig. 2 whichis a perspective view from the rear of the evaporator and from Fig. 3 which shows the sheet metal wall structure in the flat prior to bending. The evaporator 30 I1 comprises a freezing chamber formed by two upright side walls 2| and 22 and a bottom wall comprising sections 23 and 24 bent at right angles to the side walls 2| and 22 respectively,

the sections 23 and 24 serving as a freezing tray support. The side walls are joined integrally by a third upright wall 25 constituting the rear wall of the evaporator and a refrigerated freezing tray supporting shelf 26 is arranged within the freezing chamber above the bottom wall and 0 I comprises a portion of the wall structure bent at right angles to the wall 25. There are thus ers 21 and 29 are connected above and below the normal level of liquid refrigerant therein by pas- 1 sages 30 and 3! respectively and the headers 28 and 29 are similarly connected by passages 32 I and 33. A plurality of U-shaped passages 34 u I are formed within the walls 2| and 23 and communicate at their upper ends with the header 21. The lower ends of the passages 34 are connected by ducts 35 to a manifold 36 formed parallel to .the inner edge of the wall 23. The walls 22 and 24 are provided with similar U-shaped passages 31, ducts 38 and manifold 39. 25 and 26 are formed a plurality of U-shaped passages 40 communicating at their upper ends with the header 29. A refrigerant supply conduit 4| is formed in the walls 22 and 24 and communicates directly with the manifolds 36 and 39 in the bottom walls. The manifolds are connected by a tube 42 so that refrigerant admitted to the supply conduit 4| will flow into the manifolds in parallel and thence through the ducts 35 and 38 into the Ushaped passages 34 and 31 respectively. The gaseous refrigerant is withdrawn from the evaporators through the suction line 20 which is connected in communication with the header 2! above the level of liquid refrigerant therein.

The manner in which the evaporator is formed will readilybe understood by reference to Fig. 3. The wall structure comprises complementary sheet metal portions 43 and 44 which form the outer and inner sheets respectively of the evaporator, In Fig. 3 the sheets have been shown flat with the sheet 43 on top of the sheet 44, the edges of the sheet 44 being folded around the edges of the sheet 43 as indicated at 45. The wall structure comprises three adjacent wall panels, the outer two of which form the outer two wall members providing the side and bottom walls of the freezing chamber and the middle one of which forms the middle wall member providing the back wall and shelf. The inner sheet 44 is provided with portions 46 and 41, extending above the walls 2| and 22 respectively and having flanges 48 and 49 formed thereon for supporting the evaporator within the refrigerator cabinet. In Fig. 3 the lines along which the wall structure is to be bent to form the evaporator are indicated by dot and dash lines. Before the sheets 43 and 44 are secured together the indentations forming the several refrigerant passages are formed in the sheet 43 and complementary portions of the headers 21, 28 and 29 are formed in both sheets. 'I'he sheets are then secured together other suitable manner and the edges 45 of the sheet 44 are bent around the sheet 43. The outer panels are then bent along the lines 50 and 5| to form the bottom walls 23 and 24 respectively and the middle panel is bent along the line 52 to form the freezing shelf 26. The outer panels are then bent at right angles to the inner panel along the lines 53 and 54. The freezing chamber is thereby formed with the shelf 26 positioned therein above the bottom walls 23 and 24. The tube 42 is then soldered to the manifolds 36 and 39 to provide communication 'therebetween through openings 55 and 56 respectively. The entire evaporator, including the freezing shelf, is'thus formed from a single sheet metal wall structure comprising three adjacent wall members and it is not necessary to provide shelf supporting brackets and refrigerant connections to the shelf.

During the operation of the refrigerating machine, refrigerant is admitted to the manifolds 36 and 39 from the supply conduit 4| and flows through the ducts 35 and 38 which direct jets of refrigerant into the passages 34 and 37. This produces a circulation of liquid refrigerant with- Within the walls by welding, brazing, or in any.

in the passages and increases the heat absorbing capacity of the side and bottom walls. The same liquid level is maintained in all three headtained about half full of liquid refrigerant, so as to flood the passages 34, 31 and 40 with liquid refrigerant. The passages 40 in the rear wall and shelf are maintained filled with liquid refrigerant and the shelf is thereby refrigerated. The refrigerant vaporized in the passages 34, 31 and 40 rises to the'headers and flows into the header 2! from which it is withdrawn through the suction line 20.

From the foregoing, it is apparent that I have provided an evaporator for refrigerating machines which may sheet metal wall structure to provide a plurality of refrigerated freezing tray supporting surfaces and which requires a minimum number of soldered connections.

While I have described my invention in connection with a flooded evaporator for household refrigerating machines, other applications will readilybe apparent to those skilled in the art. I do not, therefore, desire my invention to be mited to the construction shown and described and I intend in the appended claims to cover all modifications within the spirit andscope of my invention. I

What I claim as new and desire to secure by Letters Patent of the United States is:

,1. An evaporator for refrigerating machines comprising a unitary wall structure including complementary sheet metal portions formed to be constructed of a single,

constitute three wall members providing two upranged to form a freezing shelf within said chamber and above the bottom wall thereof.

2. A flooded evaporator for refrigerating machines comprising a unitary wall structure including complementary sheet metal portions formed to constitute three wall members providing two upright walls spaced apart and a third upright wall connecting said two walls and integrally joined therewith, each of said wall members having formed therein a header and a plurality of depending refrigerant circulating conduits communicating therewith, said members providing said two walls being bent to form the side and bottom walls of a freezing chamber, and the third one of said members being bent to form a freezing shelf within said chamber and above the bottom wall thereof,

3. A flooded evaporator for refrigerating machines comprising complementary sheet metal portions formed to constitute three wall members providing two upright walls spaced apart and a third upright wall connecting said two walls and integrally joined therewith, each of said wall members having'formed therein a header and a plurality of depending refrigerant circulating conduits communicating therewith, the two of said members providing said two upright walls being bent to form the side and bottom walls of a freezing chamber, and the third one of said members being bent to form a freezing shelf within said chamber and above the bottom wall walls and integrally aieasse thereof,'means for admitting refrigerant to said evaporator and for directing jets of refrigerant into said depending refrigerant circulating conduits in said two members to produce a circulation of refrigerant through said conduits of said two members, means for providing communication between said headers above and below the normal level of liquid refrigerant therein, and means for conducting gaseous refrigerant from one of said headers.

4. A flooded evaporator for refrigeratingm chines comprising complementary sheet metal portions formed to constitute three wall members providing two upright walls spaced apart and a third upright wall connecting said two walls and integrally joined therewith, each of said wall members having a refrigerant header formed therein near the upper end thereof and a plurality of U-shaped refrigerant circulating conduits communicating at both ends with said header, the two of said members providing said two upright walls being bent to form the side and bottom walls of a freezing chamber and the third one of said members being bent to form a freez- -ing shelf within said chamber and above the bottom wall thereof, means including manifolds formed in the lower ends of said two wall members and a plurality of ducts providing communication between said manifolds and said depending conduits in said two members for admitting refrigerant to said evaporator and for directing Jets of refrigerant into said conduits in said two members toproduce a circulation of liquid refrigerant insaid two members, means for providing communication between said headers above and Below the normal level of liquid refrigerant therein, and means for conducting gaseous refrigerant from one of said headers.

5. An evaporator for refrigerating machines comprising a unitary wall structure including complementary sheet metal portions formed to constitute three integral wall members providing two upright walls spaced apart and a third upright wall connecting said two walls and integraily joined therewith, said wall members having refrigerant passages formed therein, the two of said wall members providing said two upright walls forming the side walls of said evaporator and the third of said wall members forming the rear wall thereof, said third member having a portion bent substantially at a right angle to said rear wall to provide a supporting surface,

and at least one of said two wall members having a portion thereof bent substantially at a right angle thereto to provide a second supporting surface.

DEL'BERT F. NEWMAN. 

